Relative Centrifugal Force (Rcf); Centrifugation Of Materials Or Mixtures Of Materials With A Density Higher Than 1.2 Kg/Dm; Haematocrit Measurement; Haematocrit Capillaries - Overview - Hettich HAEMATOKRIT 210 Mode D'emploi

12

Relative centrifugal force (RCF)

The relative centrifugal force (RCF) is given as a multiple of the acceleration of gravity (g). It is a unit-free value and
serves to compare the separation and sedimentation performance.
These values are calculated using the formula below:
RCF
RCF = relative centrifugal force
RPM = rotational speed (revolutions per minute)
r = centrifugal radius in mm = distance from the centre of the turning axis to the bottom of the centrifuge.
The relative centrifugal force (RCF) stands in relation to the revolutions per minute and the centrifugal
radius.
13

Centrifugation of materials or mixtures of materials with a density higher than 1.2 kg/dm

When centrifuging with maxim revolutions per minute the density of the materials or the material mixtures may not
3
exceed 1.2 kg/dm .
The speed must be reduced for materials or mixtures of materials with a higher density.
The permissible speed can be calculated using the following formula:
Reduced speed (n )
red
e.g.: maximum speed RPM 4000, density 1.6 kg/dm
1.2 kg/dm³
n = x 4000
red
1.6 kg/dm³
If in doubt you should obtain clarification from the manufacturer.
14

Haematocrit measurement

14.1

Haematocrit capillaries - Overview

Standard capillary tubes, Order No.: 2074
The classical heparinized haematocrit capillary tube made of glass. Tried and tested for years.
Mylar-reinforced capillary tubes, Order No.: 1072
The heparinized glass capillary is coated with plastic. Should such a capillary break the glass splinters are retained in
this coating. This means that the risk of injury for the user is reduced.
Self-sealing capillary tubes, Order No. 1071
These capillary tubes, which are also heparinized, no longer need to be sealed. They are already equipped with a
seal. At first, the seal material is air-permeable so that the capillary can be filled. The seal will only become
impermeable when it comes into contact with blood. Therefore, there will be no leaks during centrifugation.
2
 
RPM
 
  
r 1,118
 
1000
For more on the centrifugal radius see the chapter " Anhang/Appendix,
Rotoren und Zubehör/Rotors and accessories".
1.2
=
Greater density [kg/dm³]
3
RPM = 3464 RPM
RCF
 
RPM

r 1,118
x maximum speed [RPM]
EN

1000
3
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